So not true, the RT-AC68U will walk circles around any eMTA an ISP will give you. The eMTA's cable companies give are expensive because a DOCSIS 3.0 modem is already $80 on average, adding a VoIP gateway and WLAN router plus a sufficient profit margin adds up.
Well, basically, a $200 home router will peak well before maxing out a 150 mbps connection unless you turn off all the QoS, UPnP and security features... but at that point you're better off just using the eMTA (which can handle the speed because it never had any of those features in the first place).
Once again, not true. NAT and QoS are the most expensive tasks a consumer router will perform, and even at 1Gbps it's rather mundane work even for a slower CPU (the 600MHz CPU in the RT-AC66U is sufficient).
Once you start looking at the latency requirements to achieve 10GBps interconnects you're going to have issues with what you can reasonably expect from the $200 price range, but consumer networks have a long ways to go before that's going to even need to be thought about.
